Betula tree named ‘STN-01’

ABSTRACT

A new and distinct Betula nigra tree named ‘STN-01’ which is characterized by a significantly shorter tree height, a freely branching and densely foliaged growth habit, main stems and lateral branches with shortened internodal spacing, relatively large and dark green foliage, and prominent bark exfoliation of the oldest wood. The claimed plant propagates successfully by softwood stem cuttings and has proven to be uniform and stable in the resulting generations.

Latin name of the genus and species: The Latin name of the genus andspecies of the novel variety disclosed herein is Betula nigra.

Variety denomination: The inventive variety of Betula nigra disclosedherein has been given the variety denomination ‘STN-01’.

BACKGROUND OF THE INVENTION

Parentage: The claimed tree is a seedling selection of unknown parentagewhich was discovered at a commercial tree nursery in McAlpin, Fla. Inthe spring of 2004, the claimed plant was discovered growing amongst apopulation of openly-pollinated, unnamed Betula nigra trees (notpatented) which were in cultivation in 20 gallon nursery containers.Said tree exhibited a dwarfed and densely foliaged growth habit whencompared to other Betula nigra progeny in the population and otherspecimens that typify the species. The tree was isolated and grown foran additional year to confirm the distinctness and stability of thecharacteristics initially observed. Upon further evaluation andconfirmation of the desirable traits, the claimed tree was selected forcommercialization.

Asexual Reproduction: In 2005, ‘STN-01’ was first asexually reproducedby way of softwood stem cuttings in McAlpin, Fla. The claimed tree wasfound to asexually reproduce in uniform and stable manner and 10successive cycles of vegetative propagation have proven to be true totype.

SUMMARY OF THE INVENTION

The following characteristics have been repeatedly observed andrepresent the distinguishing characteristics of the new Betula nigratree, ‘STN-01’. These traits, in combination, distinguish ‘STN-01’ as anew and distinct cultivar.

-   -   1. ‘STN-01’ exhibits a significantly shorter tree height with a        freely branching and densely foliaged growth habit; and    -   2. ‘STN-01’ exhibits main stems and lateral branches with        shortened nodal spacing; and    -   3. ‘STN-01’ exhibits relatively large, dark green foliage; and    -   4. ‘STN-01’ exhibits prominent bark exfoliation.

BRIEF DESCRIPTION OF THE FIGURE

FIG. 1 illustrates, as nearly true as it is reasonably possible to makethe same in color photographs of this type, a field-grown ‘STN-01’ treeat approximately 7 years of age, during spring in McAlpin, Fla.

FIG. 2 illustrates, as nearly true as it is reasonably possible to makethe same in color photographs of this type, the exemplary mature foliageof ‘STN-01’.

FIG. 3 illustrates, as nearly true as it is reasonably possible to makethe same in color photographs of this type, the oldest wood of afield-grown ‘STN-01’ tree at approximately 7 years of age, during springin McAlpin, Fla. Of note is the high degree of bark exfoliation.

BOTANICAL DESCRIPTION OF THE PLANT

The following is a detailed botanical description of a new and distinctBetula nigra plant cultivar known as ‘STN-01’. Plant observations weremade on a field-grown 7 year-old tree in McAlpin, Fla. The observed treewas grown in full exposure to natural sunlight, and maintained with dripirrigation. No pest or pathogen countermeasures were employed.Observation data was recorded in April of 2020.

Those skilled in the art will appreciate that certain characteristicswill vary with older or, conversely, younger plants. ‘STN-01’ has notbeen observed under all possible environmental conditions. Wheredimensions, sizes, colors and other characteristics are given, it is tobe understood that such characteristics are approximations or averagesset forth as accurately as practicable. The phenotype of the variety mayvary with variations in the environment such as season, temperature,light intensity, day length, cultural conditions and the like. Colornotations are based on The Royal Horticultural Society Colour Chart, TheRoyal Horticultural Society, London, 1986 edition except where commonterms of color are used.

A botanical description of ‘STN-01’ and comparisons with the presumedparent and most similar commercial cultivar are provided below.

-   General plant description:    -   -   Plant habit.—Monoecious deciduous tree with an upright            ascending, freely branching growth habit.        -   Tree crown profile.—Pyramidal and maturing to rotund, when            cultivated as a single trunk; when cultivated as a            multi-trunked tree, the profile is irregularly rotund.        -   Dimensions.—The original tree grew to approximately 7.5 to            8.0 meters tall and 3.0 to 3.5 meters wide.        -   Environmental tolerances.—Hardy in US Hardiness Zones 5            through 9; prefers cooler climates with moist, loamy soils            and full to filtered sun exposure but will tolerate hotter,            dryer conditions.        -   Pest and disease susceptibility or resistance.—Plants have            not been observed to be susceptible or resistant to            pathogens and pests common to Betula nigra.        -   Propagation.—Propagation is accomplished using softwood stem            cuttings.        -   Crop time.—Approximately one growing seasons are needed to            produce a fully rooted 2 gallon nursery container that is            ready for transplant into larger nursery containers or            directly into the ground for field production.-   Root system:    -   -   Description.—A network of fibrous, non-fleshy roots.        -   Rooting habit.—Freely branching, moderately dense, and            relatively shallow in the soil profile.-   Stems:    -   -   Branching habit.—A dominant, near-vertical central main            stem, typically unbranched, gives rise to an abundance of            lateral branches, themselves freely branching. ‘STN-01’ can            be cultivated as a multi-trunked tree through human            intervention. Main stem; central leader — Quantity — One;            occasionally branching. Attitude — Erect; near vertical.            Aspect — Generally rounded. Diameter — 6.0 to 8.0 cm, at the            base of the trunk. Strength — Very strong. Texture — Smooth            and becoming progressively fissured and furrowed with age,            followed by exfoliation of the bark in large thin, papery            sheets, revealing a smooth surface beneath. Exfoliation is            most prevalent towards the base of the main stem. Exfoliated            sections of bark are clinging and become progressively            curled inward from the margins. Color, juvenile — Nearest to            a mixture of greyed-orange, RHS 166A, and yellow-green, RHS            152A. Color, mature — Newly exfoliated wood is            greyed-orange, RHS 164D and fades to orange-white, nearest            to in between RHS 159B and 159C, and ultimately to            greyed-green, nearest to in between RHS 196A and 197D.            Portions of sloughed off bark, outer surface — Irregularly            blotched with varying shades of greyed-green RHS 197A, 197B,            197C, 196B and 196C. Moderately suffused with a mixture of            green, RHS 144A, and yellow-green, RHS 146D. Fissures are            nearest to a mixture of grey, RHS 201A, and brown, 200C.            Portions of sloughed off bark, inner surface —            Greyed-orange, RHS 164D and fades to greyed-green, nearest            to in between RHS 196A and 197D. Lateral branches — Branch            angle to main axis — In between 60 and 70 degrees. Aspect —            Round. Diameter — 7.0 mm at the base. Color, juvenile —            Yellow-green, nearest to in between RHS 146A and 147C.            Color, mature — Nearest to a mixture of greyed-orange, RHS            166A, and yellow-green, RHS 152A. Texture and luster,            juvenile — Moderately pubescent and matte. Texture and            luster, mature — Glabrous, moderately glossy, and moderately            lenticellate. Lenticels are irregularly elliptical to            elliptical and range in size from 0.25 mm to 1.0 mm long and            0.25 to 0.5 mm wide; color is greyed-green, nearest to in            between RHS 197D and 198D. Stem strength — Strong.-   Foliage:    -   -   Arrangement.—Alternate.        -   Attachment.—Petiolate.        -   Division.—Simple.        -   Shape.—Rhomboid to ovate.        -   Length.—77 mm.        -   Width.—44 mm.        -   Apex.—Acute.        -   Base.—Obtuse.        -   Margin.—Doubly serrate; occasionally slightly undulated.        -   Aspect.—Flat to longitudinally concave; occasionally with a            slight axial twist and occasionally reflexed.        -   Texture and pubescence, adaxial surface.—Glabrous, and            glossy.        -   Texture and pubescence, abaxial surface.—Pubescent and            matte. Juvenile foliage, adaxial surface — Yellow-green,            nearest to in between RHS 148A and 148B. Juvenile foliage,            abaxial surface — Yellow-green, nearest to in between RHS            148B and 148C. Mature foliage, adaxial surface —            Yellow-green, RHS 148A. Mature foliage, abaxial surface —            Yellow-green, nearest to in between RHS 146B and 146C.        -   Venation.—Pattern — Pinnate. Vein color, adaxial surface —            Yellow-green, nearest to RHS 146D. Vein color, abaxial            surface — Yellow-green, nearest to RHS 146D.        -   Petiole.—Length — 10.0 to 12.0 mm. Diameter — 1.5 to 2.0 mm.            Color — Yellow-green, nearest to a mixture of RHS 146D.            Texture, adaxial and abaxial surfaces — Moderately            pubescent.        -   Stipules.—Absent.-   Inflorescence: To date, no flowering has been observed on the mother    plant or any progeny therefrom.-   Flower bud: To date, no flowering has been observed on the mother    plant or any progeny therefrom.-   Flower: To date, no flowering has been observed on the mother plant    or any progeny therefrom.-   Reproductive organs: To date, no flowering has been observed on the    mother plant or any progeny therefrom.-   Fruit and seed: To date, no fruiting has been observed on the mother    plant or any progeny therefrom.

COMPARISON WITH THE PRESUMED PARENT PLANT

Plants of the new cultivar ‘STN-01’ differ from the parent, an unnamedBetula nigra tree (not patented), by the characteristics described inTable 1. The pollen parent is presumed to also be an unnamed Betulanigra tree (not patented), and therefore no additional comparison to thepollen parent is disclosed.

TABLE 1 Characteristic ‘STN-01’ The parent Tree height. Significantlyshorter than Much taller than the parent; approximately ‘STN-01’. 50percent shorter. Internode spacing. Significantly shorter. Significantlylonger. Abundance of More abundant. Less abundant. foliage. Foliagesize. Larger and broader Smaller than ‘STN-01’. than the parent. Generalcoloration Darker shade of green Lighter shade of green of the foliage,relative to the parent. compared to ‘STN-01’. Exfoliation of the Morepronounced Less pronounced older wood. relative to the parent. comparedto ‘STN-01’.

COMPARISON WITH THE MOST SIMILAR BETULA NIGRA CULTIVAR KNOWN TO THEINVENTOR

Plants of the new cultivar ‘STN-01’ are most similar to the commercialcultivar, Betula nigra ‘BMNTF’ (not patented). A comparison of ‘STN-01’with Betula nigra ‘BMNTF’ is described in Table 2.

TABLE 2 Characteristic ‘STN-01’ ‘BMNTF’ Internode spacing. Significantlyshorter. Significantly longer. Foliage shape. Broader than ‘BMNTF’.Narrower than ‘STN-01’. General coloration Darker shade of green Lightershade of green of the foliage, relative to ‘BMNTF’. compared to‘STN-01’. Exfoliation of the More pronounced Less pronounced older wood.relative to ‘BMNTF’. compared to ‘STN-01’.

That which is claimed is:
 1. A new and distinct variety of Betula nigratree named ‘STN-01’, substantially as described and illustrated herein.